Brown tetrakisazo dyestuff and its heavy metal complex compounds



United States Patent-'0 C 2330379 fi h tented Apr. 15, 1958 able brown leather dyestufi the shade of which is more 2,830,979 yellowish and which is particularly distinguished by a BROWN TETRAKISAZO DYESTUFF AND ITS fasmessm waterand i HEAVY METAL COMPLEX COMPOUNDS These many good properties of the new tetrakisazo v V V 5 dyestufi and its metal complex compounds amount to a Hermann Goehei and Eugen Giietehhel'g, Levelkllsellvery valuable advance in the field of the brown leather Bayerwerk, Germany, assignors to Farbenfabriken d fh Bayer Aktiengesellschaft; Leverkusen, Germany, a corh Duration of Germany T e following examples illustrate the invention, the

. parts being by weight: No Drawing. Application January 26, 1955 Serial No. 484,293 Th d ff d k J p e monoazo, yestu prepare 1n nown manner Claims Germany Februarylgi 1954 from 341 partsof diazotized l-aminoa8-hydroxynaph- Example 1 m 6 4 thalene-3,6-disulfonic acid (monosodium salt) and 110 parts of 1,3-dihydroxybenzene by coupling in soda alka- The present invention relates to a new tetrakisazo dyeline medium is coupled in the Presence of sodium stuff and to its heavy metal complex compounds. behate with the diazo compound of 220 Parts Of The n w t tr ki bfl mfi conespcnds to the foldinitro-Z-amino-l-hydroxybenzene. After the coupling lowing'formula is finished, the neutralized dyestufi solution is coupled at I N=.N p HO ptqvQ-on no No nois- -soin This new dyestulf'may be ob t ain'ed by coupling in about a temperature of 10: C. with the diazo solution of 276 molar quantities diazotized l-amino-8-hydroxynaphthaparts of 4-nitro-1-am1nobenzene which has been rendered lene-3,6-disulfonic acid with 1,3 -dihydroxy-b'en2ene in neutral to Congo-red paper and clarified. After the coualkaline medium, further coupling this monoazo dyestutt pling is complete, the tetraklsazo dyestuff is isolated from with diazotized 4,6-dinitro-2-amino-l-hydroxybenzene in weakly acid medium by adding sodium chloride and weakly alkaline medium, and finally coupling the disazo dried. When ground, it represents a black-brown powdyestuft with two mols of diazotized 4-nitroi-l-aiiiinobeh-i ldei'uwhieh dyes l'chrome-, vegetableand synthetic-tanned zone in weakly acid medium. It is, however, possible to t leatherin deep and full brown shades of very good fastmake this tetrakisazo dyestuff also by coupling diazotized mess to acid, formaldehyde and solvents, as well as of goodfastness to t he hardness of water and to light.

4-nitro-l-aminobenzene with l-am'ino-S-hydrQXynaphtha-' v v By converting the isolated dyestufi in known manner lone-3,6-disulfonic acid in alkaline or acetic acid medium;

diazotizing the monoazo dyestuff and coupling the diazo into its iron complex compound, a more yellowish dyecompound with 1,3-dihydroxybenzene in alkaline medi u n, I p stuflf s obtained which excels the metalfree dyestulf by its further coupling this disazo dyestufi with diazotized '4,6- Improved, very good fastness to water and washing.

dinitro-Z-amino-l-hydroxybenzrie in weaklyalkaline E l 2 medium, and finally coupling the trisazo dyestufi again xamp e with diazotized 4-nitro-1-aminobenzene in weakly acid A diazotized and clarified solution of 152 Parts of medium 4-nitro-1-aminobenzene is coupled at low temperature in The new dyestuff is especially suited for dyeing chrome e Presence of sodium carbonate with Parts tanned upper, chrome velvet as well as leather tanned ammo's'hydl'oxynaphthalehe-3fi-tilsilitohle acid with vegetable tannins and synthetic tanning agents. It P h After the Coupling is h Y Q- yields on these kinds of leather very bright and full brown tic acid i adfied whereupon the flmlIlOaZO y stuff 1 shades of good conformity of the shades. Besides the furthet diazotized 111 i manner and e p at good solubility of the dyestufi, the deep bloomy brown i the Pitsence of sofiium cahhohate with 110 Parts shades it yields on velvet leather, and its good levelling of i3'd1hYdmXYbei1Zehe, dissolved in 2000 Parts Of Water Power are Particularly to be mentioned. 1 i and 125 partsof a 30 percent caustic soda solution. 28() proved fastness to buffing is to be pointed out in which R s 0f 4,6-d1I11ti0-2-am1m'ihydroxyhenzene are d1az oproperty it excels the trisazo dyestuff known from Swiss t1Zed ih knPwn i are eoilpieti as an acetic acid Patent No. 116,360 by coupling diazotized 4,6-dinitro-2- 591M103 with h disaz? lf 1h weakly aikeilhe amino-l-hydroxybenzene with 1,3-dihydroxybenzene in h- Aftei' this eollpilhg s p ei the reaction P alkaline medium, coupling the monoazo dyestuff with coupled with the e solution of P 0f diazotized l-amino-8-hydroxynaphtha1ene-3,6-disulfonic tmltro-hammobenlene which has been Clarified and acid and finally coupling this diazo dyestuff with di'azorendered nehttfii t0 cohgo'red P p after one 01 i1 tiled 4 nit1-O 1 aminobenzene in acetic acid medium, the 20 percent sodium carbonate solution is allowed to run components being used in molar proportions in until the final pH value is 8.5. Thereafter, sodium The new d t ff is f th distinguished by a very chloride is added and the tetrakisazo dyestuif is filtered good fastness to acids and f ld h d Its fasmess at litmus acid reaction. After it has been dried and to h h d of wateris 1 ground, the dyesttf represents a black-brown powder Since the new dyestufi contains a group of two hydroxy which is Particularly suited for the dyeing Of Chrome radicals in o-position to an azo bridge it can be treated PP chrome Velvet as Well s O vegetableand synin usual manner with agents yielding metal. Of the varithetictahtied ieather- The dyeihgs 011 Velvet are P ous heavy metal complex compounds thus obtainable the l rly to be m ntioned ecause of their deep, bloomy iron complex compound proved to be a particularly valuviolet-brown shades showing very good fastness to buffing.

t r 3 t 4 The fastness to acid,formaldehyde as well as to solvents We claim: is very good, the fastness to the hardness of water and '1. A dyestufi selectedfrom the group consisting of the to light is'good. tetrakisazo dyestufi corresponding as free acid to the By converting lgnown manner the, isolated dyestufi formula 15 and its iron complex compounds.

2. The iron complex compound of the tetrakisazo dyestuff corresponding as free acid to the formula into its iron complex compound, a more yellowish dyestuff is obtained which excels the metal-tree dyestuff by HO O1NON= N0,

its improved, very good fastness to washing and water. Atetrakisazo dyestufi corresponding to the formula no N=NQOH H NO:

om-Gums H N=NG 1 1101s sodI References Cited in the file of this patent UNITED STATES PATENTS Re. 22,046 Fellmer Mar. 10, 1942 1,697,122 Krech et al. Ian. 1, 1929 2,139,472 Schubert Dec. 6, 1938 FOREIGN PATENTS 116,360 Switzerland Aug. 16, 1926 

1. A DYESTUFF SELECTED FROM THE GROUP CONSISTING OF THE TETRAKISAZO DYESTUFF AS FREE ACID TO THE FORMULA 